STAMFORD — Purdue Pharma was sued this week by the state of New Hampshire for alleged marketing violations tied to its prescription opioid OxyContin, practices that officials cite as a contributor to the state’s opioid crisis.

Drawing on evidence from a two-year investigation, the complaint accuses Purdue of breaking a number of state laws through a range of “unfair or deceptive” tactics. The Stamford-based firm significantly downplayed OxyContin’s risk of addiction, made dubious claims about the drug lasting for 12 hours and being tamper resistant, and failed to report suspicious dispensing, according to the lawsuit.

“To defeat the epidemic, we must stop creating new users,” state Deputy Attorney General Ann Rice said in a statement. “And part of that is making sure these highly addictive and dangerous drugs are marketed truthfully and without deception and in such a way as not to minimize addiction risks or overstate benefits to patients.”

Sales representatives of Purdue made calls to more prescribers in New Hampshire than any other maker of branded opioids, comprising two of every three such calls in the state, according to the complaint. The company allegedly maintained a state sales force of four to six representatives who were each given the goal by the company of seeing six to seven prescribers per day. From 2013 through 2015, Purdue met with 256 prescribers in the state during which the salesperson provided a meal, coffee or other benefits to the prescriber, the complaint said.

In a statement, Purdue officials said they denied the lawsuit’s allegations, but shared New Hampshire officials’ concerns about the opioid crisis and are “committed to working collaboratively to find solutions.”

“OxyContin accounts for less than 2 percent of the opioid analgesic prescription market nationally,” Purdue also said in the statement. “But we are an industry leader in the development of abuse-deterrent technology, advocating for the use of prescription drug monitoring programs and supporting access to naloxone — all important components for combating the opioid crisis.”

Rice said the state is suffering from a severe opioid epidemic, pointing to nearly 500 overdose deaths last year, almost 10 times the total in 2000. In 2016, the U.S. Drug Enforcement Agency deputy administrator called New Hampshire “ground zero” of the opioid epidemic.

Purdue has faced a series of similar lawsuits in the past few months related to other allegations of fraudulent OxyContin marketing, which the plaintiffs blame for fueling the opioid crisis in their areas. Other recent complaints have been filed by the states of Ohio and Oklahoma, the city of Everett, Wash., and district attorneys in northeast Tennessee.